Acta Dermato-Venereologica 99-13CompleteContent | Page 34

1311 SHORT COMMUNICATION A Case of Malignant Melanoma Arising in Nagashima-type Palmoplantar Keratosis Sho KATAYAMA, Toshifumi NOMURA*, Masae TAKEDA, Toshinari MIYAUCHI, Shotaro SUZUKI, Jin Teng PEH, Takuma NOHARA, Shinya KITAMURA, Hiroo HATA and Hiroshi SHIMIZU Department of Dermatology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan. *E-mail: [email protected] Accepted Sep 25, 2019; E-published Sep 25, 2019 Nagashima-type palmoplantar keratosis (NPPK), the most common palmoplantar keratoderma (PPK) in East Asia, is characterized by well-demarcated erythema with mild-to-moderate hyperkeratosis on the palms and soles with transgrediens (1, 2). Biallelic loss-of-function mutations in SERPINB7 are responsible for NPPK (1, 2). We report here a case of NPPK with malignant me- lanoma (MM). CASE REPORT A 45-year-old Chinese woman presented to our hospital with a 10-year history of a black macule on her left foot, which had gradually increased in size. Physical examina- tion revealed an irregularly pigmented macule of 45×25 mm on the base of her left hallux (Fig. 1a), which had a parallel ridge pattern and asymmetry of colours on dermoscopy (Fig. 1b). Bilateral erythematous hyper- keratotic lesions were also noted on the palms and soles, showing transgrediens and a whitish spongy appearance soon after water exposure. Her siblings presented with similar hyperkeratotic lesions, whereas her parents were not affected. The findings led to the clinical diagnosis of MM in situ and NPPK. The black macular lesion was excised with a 5-mm margin. The wound was reconstructed using a full- thickness skin graft from the right abdomen. Histology revealed the proliferation of atypical melanocytes that were positive for Sox 10, Melan A, and HMB-45 in the epidermis. Parakeratosis limited to the lower layers of the stratum corneum, which is characteristic of NPPK (2), was also noted. To confirm the diagnosis of NPPK, mutation analysis of SERPINB7 was performed. Brief­ ly, genomic DNA was extracted from peripheral blood using the QIAamp DNA Blood Maxi Kit (Qiagen, MD, USA) and analysed by Sanger sequencing, as described previously (2). The patient provided written informed consent to participate in this study, in compliance with the Declaration of Helsinki. The Institutional Review Board at the Hokkaido University Graduate School of Medicine approved this study (project No. 14-063). Mu- tation analysis led to identification of the homozygous Fig. 1. (a) A black macule with colour variegation at the base of the left hallux that had gradually increased in size. Diffuse erythema and hyperkeratosis are noted on palmoplantar skin. (b) The macule shows a parallel ridge pattern and asymmetry of colours under dermoscopy. (c) The patient carries the homozygous nonsense mutation c.796C>T (p.Arg266Ter) in SERPINB7. (d) The grafted skin shows no remarkable change after 15 min water exposure, whereas the surrounding affected skin shows a whitish spongy appearance. This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2019 Acta Dermato-Venereologica. doi: 10.2340/00015555-3326 Acta Derm Venereol 2019; 99: 1311–1312